As Ive suggested in this column and elsewhere, I sometimes worry that crooks might be intercepting my wireless transmissions. (I once explained, in a Wired News article, that tin foil hats really do block radio signals.)

That said, I use RFID all the time.

I frequently tap my RFID-tagged MasterCard PayPass against the wireless readers at CVS or Petco, for example, to make payments from my checking account. But first I have to fish the card out of my overstuffed wallet. And then I must pull the plastic out of its RFID-blocking Secure Sleeve (www.idstronghold.com).

Writing a check couldnt take much longer.

Thank the gods, then, for Eclectyk, a system designed by MIT students to replace credit and customer loyalty cards with a single RFID-equipped phone.

Eclectyk stores your credit card data in your phone. It also automatically selects the right customer loyalty card information for your purchase, depending on which store you happen to be in.

We will soon be able to get rid of our keys, too. The MIT students, Chenxia Liu, Jenny Liu, and Kevin Modzlewski, have demonstrated how Eclectyk will unlock wirelessly controlled door locks.

Eclectyk (www.youtube.com/watch?v=2WF2L0iC6Tw) uses the RFID standard called NFC - the same one found in the PayPass card. NFC, or Near Field Communication, calls for devices to be within four centimeters of each other to communicate wirelessly.

Eclectyk adds further safeguards against rogue readers.

And it includes a remote wipe function, so you can delete your credit card info from anywhere, if your phone gets nicked.

Precious few phones are capable of Near Field Communication, not to mention WiFi. Nokia, a participant in the Eclectyk project, sells a handful of NFC phones.

But NFC is gaining acceptance among shoppers, thanks largely to the success of PayPass. And the technology can be incorporated into existing phones through their SIM and MicroSD card slots.

The Eclectyk kids plan to commercialize their system, which is in the running for a sizable NFC industry prize.

Urban survival

iPhone runs tackle against meter maids
It is really a marvel to watch Brooklines meter maids fan out across Coolidge Corner at 8 a.m. on weekdays. Strolling down Harvard and Steadman streets, they methodically drop their tickets and move on, faster than you can score a black coffee at Peets and rush back to your car.

A new iPhone app will give you a jump on these suspected Cylons, by reminding you where you parked and alerting you to scheduled street sweeping days and snow emergency days.

The app, Sweep:Bos (http://www.thesweeperinc.com/), covers many Boston-area neighborhoods, inside and outside of the city. (Alas, Brookline is not on the list yet.) The app is updated regularly.

As a street-sweeping day draws near to your spot, Sweep:Boss background (which resembles the ticket you are trying to avoid), turns from green to yellow to red.

Developers Chris DeOrio and Howard Nager are local boys. DeOrio honed his parallel-parking skills in the North End Nager is from Southie.

They will soon release versions of Sweep for San Francisco and Chicago, even as they continue to add Boston neighborhoods. They are also working on a version of the app for the BlackBerry